Offshore submerged pipelines are installed usually either by dragging the pipeline along the seabottom, pulling the pipeline while maintaining it in buoyant condition, or deploying the pipeline from a conventional lay barge. Pipe laying procedures involving moving contact between the pipeline and either the seabed or handling equipment may be damaging to the pipeline, particularly if the pipeline is coated with a material sensitive to abrasion, or in cases where existing pipelines need to be crossed and contact with them needs to be avoided.
A principal purpose of the present invention is to provide a system for installing offshore submerged pipelines by pulling them through the water while providing means for supporting the pipeline during the pull so that the pipeline does not touch the seabed and avoids abrasive contact with the seabed and other obstructions or existing pipelines.
Applicants are not aware of any prior art references which, in their judgment as those skilled in the pipeline art, would anticipate or render obvious the novel pipelay system of this invention; however, for the purposes of fully developing the background of the invention and establishing the state of the requisite art, the following are set forth: U.S. Pat. Nos. 3,849,997; 4,107,933; 4,191,494; 4,326,821; 4,474,507.